sleaz22xx

Tranny tunnel around my A/T has been getting very hot as of recent, Today on the highway the A/T oil temp light finally came on. Pulled over let it cool, checked the fluid level and it was high. When i got to my destination i drained the pan (look burnt) and filled tranny to the appropriate level.

On the way home Tranny is still getting very hot and now i am getting a wierd noise on the highway when rpms drop to between 2500-2100(sounds like a vibrating grating noise). Also the tach drops dramatically to just under 2k

Other than the problem stated above, the tranny shifts nice and smooth.

Has anyone experienced similar symptoms or having any suggestions on how to save my tranny.

Is the tranny gone!?!?

Thanx in advance

InternetRoadkill

Sounds like a clutch is failing in it. Burned fluid is usually a bad sign.

bigtrucknwheels

torque converter is my guess.

I'll soon have an entire, perfect a340h for sale...

JDMSLIK

How many miles on the vehicle and how old is the radiator. Your ATF cooler sounds like it's plugging. I'd put an aftermarket cooler in first and see what happens.

sleaz22xx

around 110k on the truck , as far as i know its th original rad. What really concerns me is the vibrating grattig noise it make when rpms drop to around 2400-2100. any one one what this my be and if its salvagable?

InternetRoadkill

Actually, the torque converter has a clutch in it for locking up around those rpms in cruise. I think there's a way to disable the lockup, but I don't remember how. It may involve unplugging the electrics to the tranny. I'm not sure if the O/D switch disables the lockup or not.

bigtrucknwheels

I was told the ECT button disables TCC lockup. but I am not positive on that one.

InternetRoadkill

If I'm understanding the FSM correctly, it looks like you can force the torque converter to unlock by applying the brakes enough to get the brake lights to come on. You can also keep the torque converter from locking up by placing the shifter in '2' which locks the tranny in 3rd gear with no lock-up.

If the noise goes away, it's time for a new torque converter. I feel for yah. I just changed mine.

sleaz22xx

I can only repeat the noise when the truck is over 50 mph, and between 2000-2300 rpm. Do you think "2" would be safe at these speeds?

Furthermore if I through it in "N" at around 50 , the noise will occur regardless of rpm. It sounds like a fast rattling coming from right below the tranny tunnel. Thanks for the help roadkill, ive been reading some of your post

InternetRoadkill

Should be safe to run 50 in '2'. That's 3rd gear. Just watch your tach if your worried.

Does the noise change pitch in 'N' when you rev the engine?

sleaz22xx

Doesnt change pitch but gets slower or faster with regard to RPM

InternetRoadkill

Well that's what I meant. (Bad word choice on "pitch".) I think your torque converter has moved up to prime suspect status. No fun to change, but it's better than rebuilding a tranny.

You should flush and drain the fluid as well as change the filters (There's two: one in the tranny and another in the transfer case) when the torque converter gets replaced. If the converter is shedding metal, you want the dirty fluid out of there.